Methyl green (MG) film has been grown for the first time on p-Ge semiconductor using a simple and low-cost drop coating method. The current-voltage (I-V) characteristics of Al/p-Ge and Al/MG/p-Ge diodes have been investigated in the temperature range of 20-300K. A potential barrier height as high as 0.82eV has been achieved for Al/MG/p-Ge diode, which has high rectification rate, at room temperature. It is seen that the barrier height of the Al/MG/p-Ge diode at the room temperature is larger than that of Al/p-Ge diode and ideality factor value of 1.14 calculated for Al/MG/p-Ge diode is lower than Al/p-Ge diode. The temperature coefficient of barrier height of the Al/MG/p-Ge diode has been calculated as 2.6meV/K. The evaluation of current-voltage characteristics shows that the barrier height of the diode increases with the increasing temperature.